Multivalve control station for servomotors



R. R. STEVENS MULTIVALVE CONTROL STATION FOR SERVOMOTORS Filed Jan. 21,1947 June 21, 1949;

2 Shee'ts-Sheet l INVENTOR BoyBfizeuem QTTORNEY v 9;; 7 Ala RRT E 83June 21, 1949.

MULTIVALVE CONTROL Filed Jan. 21, 1.947

R. R. STEVENS STATION FOR SERVOMOTORS 2 Sheets$he'et 2 IN VEN TOR B.Stevens 96L) ATTORNEY Patented June 21, 1949 UNITED ATENT OFFICEMULTIVALVE CONTROL STATION FOR SERVOMOTORS Application January 21, 1947,Serial No. 723,327

14 Claims. 1

This invention relates to control apparatus and more particularly to themultiple station type.

It is often desired to control operation of a device, such as a variablepitch ships propeller, by operation of any one of a plurality ofoperators control devices located at dilferent control stations, and itis further desirable, at times, that the operating handle of theoperators control device at the non-control station or stations followmovement of and be at all times positioned like the handle of theoperators control device at the selected control station, so that whenthe control is transferred from one station to another there will be noappreciable change in the adjustment of the device being controlled.

The principal object of the invention is the provision of an improvedmultiple station control apparatus for accomplishing the above result.

Other objects and advantages will become apparent from the followingmore detailed description of the invention.

In the accompanying drawings; Fig. 1 is a diagrammatic view, partly insection and partly in outline, of a two station control apparatuscinbodying the invention; Fig. 2 is a sectional view, at an enlargedscale, taken on line 2--2 in Fig. 1; and Fig. 3 is a diagrammatic view,partly in section and partly in outline of a control apparatus for morethan two stations and embodying the invention.

DescriptionFig. 1

As shown in Fig. 1, I designates a device which it is desired tocontrol; 2, 2a designates two operators control devices adapted to belocated at difierent control stations for controlling the device l; 3designates a selector valve device for selecting the control station; 4designates a double check valve; and 5, 5a designates two like checkvalve and choke devices.

Each of the operators control devices 2, 2a comprises a body 6 and acover l removably mounted on the upper face thereof. Disposed in thebody I is a self-lapping supply and release valve mechanism 8 comprisinga two part casing 9, 9a between which is clamped around its periphery aflexible diaphragm Ill. The diaphragm it and the casing part 9 define acontrol chamber l l at one side of the diaphragm and the diaphragmtogether with the casing part 90. defines a chamber l2 at the oppositeside, the chamber l2 being open to atmosphere through an opening it.Mounted in chamber l l against one side of the diaphragm is a follower l4 having a stud portion l5 extending centrally through said diaphragminto chamber I2 and also extending centrally through a follower 55 plateIt disposed in chamber 12 in contact with the opposite side of thediaphragm. A nut I! on the stud portion I5 is tightened against thefollower plate [6 for securely clamping said plate and the follower I4to opposite sides of the diaphragm. A control spring l8 contained inchamber [2 has one end bearing against the follower plate it while theopposite end is supported on a spring seat l9. The seat I9 is in turnsupported on one end of an adjusting screw 2!) having screwthreadedengagement with the casing part 9a and extending to the exteriorthereof.

The casing part 9 has a bore open to chamber H in coaxial relation withthe diaphragm it, and slidably mounted in this bore adjacent thediaphragm is a cylindrical extension 2| of the diaphragm follower l4.Slidably mounted in the bore above the extension 2| is a relativelymovable plunger or piston 22 one end of which cooperates with saidextension to form a pressure chamber 23 which is open to a control pipe2t and through a restricted port 25 with chamber H. The follower l4 andstud portion l5 and extension 2| thereof have an axial bore 26 open atone end to chamber 23 by way of a cavity 21 in said extension and openat the opposite end to a cross bore 28a opening to chamber l2. Containedin cavity 21 is a fluid pressure release valve 26 arranged to seat onextension 2i for closing communication between said cavity and chamber23, and the bore 25.

The plunger or piston 22 has an internal chamber 29 open through one ormore radial bores 3G to an annular cavity 3| provided in the exteriorsurface of said piston. The cavity 3| is open to a fluid pressure supplypipe 32. The chamber 29 is also open through an axial bore in piston 22to chamber 23 and contains a fluid pressure supply valve 33 arranged tocooperate with the piston 22 around the adjacent end of said bore toclose communication between said chamber and bore, said valve beingconnected to one end of a pin 35 loosely extending through said boreinto chamber 23 wherein the release valve 28 is connected to theopposite end of said pin. A bias spring 35 contained in chamber 29 actson the supply valve 33 for urging it to its closed position. A spring 36contained in chamber 23 acts on adjacent ends of piston 22 and thediaphragm fol-- lower extension 2| for urging said piston in a directionaway from said extension.

A follower finger 31 having one end fulcrumed on a pin 38 carried by thebody portion 9 has one side of its opposite cylindrical like endengaging the end of the piston 22 which projects from the body portion9a. The other side of the cylindrical like end of finger 31 is engagedby an adjustable arcuate shaped cam element 39 pivotally connected atone end by a pin 40 to a hub 4| of an operators lever 42, said hub beingjournaled on a shaft 43 carried by the body 6 directly above the upperend of piston 23 and with its axis at right angles to that of saidpiston. The opposite end of the cam element 39 has a slot in which isdisposed an eccentric portion 44 of an adjusting screw 45 extendingthrough the hub 4| from side to side and having on one end a head 46engaging one side of said hub and on the other end a lock nut 41 forengaging the opposite side.

The cover I has a slot 48 extending transversely of shaft 63 throughwhich the lever 42 extends to the exterior of the control device.

Disposed in the casing 6 of the control' device at one side of theoperators control lever hub M, is a structure 49 for holding said leveragainst accidental movement by vibration or the like. This structure 41comprises a casing containing a flexible diaphragm 50 clamped around itsedge and cooperating with the casing to form at one side a controlchamber 5| open to pipe 32 and to form at the opposite side a chamber 52open to atmosphere. Secured to the center of diaphragm and projectingtherefrom through chamber 52 into a bore in the casing is a plunger 53arranged at one side of the hub 4| at right angles to the axis thereof.In this bore is also slidably mounted a friction shoe 54 having on oneend an arouate surface which is arranged to slidably and frictionallycontact the peripheral surface of hub ll. The shoe 54. has a cross slotopen to the opposite end thereof, and carried by the casing andextending through this slot is a pin 55 for holding the arcuate surfaceof the shoe in working alignment with the peripheral surface of the hub.A spring 56 acts on diaphragm 50 for urging same and plunger 53 in adirection away from hub 4| to permit disengagement of shoe 56 from saidhub.

The casing part 9 of the supply and release valve mechanism 8 has anopen ended chamber in which is slidably mounted a fulcrum piston 5'! ofa fulcrum device ||l5. The piston 5'! has a hollow rod 58 mounted toslide in a bore provided axially through a stop member 59 secured in theopen end of said bore. The face of piston 51 from which rod 58 extendsis open to atmosphere through clearance space (not apparent in. thedrawing) between said. rod and the wall of the bore through member 59and a felt dust excluding ring 60 carried by said member and havingsliding contact with the surface of said rod. Atv the opposite side ofpiston 51 is a control chamber 6| open to a pipe 62.

A fulcrum pin 63 is carried in the end of the fulcrum piston stem 58 anda lever 64, intermediate its ends, is fulcrumed on said pin. One end oflever 64 is in the form of a screw-threaded stud 65 and adjustablymounted on this stud is a clevis 56 and a lock nut 61 for engaging. theend. thereof for looking it in an adjusted position on said lever.Connected to the opposite end ofv clevis 66 by a pin 68 is one end of alink 69 the opposite end of which is connected to the adjustable camfulcrum pin 40.

The opposite end of lever 64 is pivotally connected by a pin 70 to oneend of a screw-threaded member upon which is adjustably mounted a clevisl2 and a lock nut 13 for engaging one end of said clevis for securingsame on said member in an adjusted position. The opposite end of clevis72 is pivotally connected by a pin 14' to one end of a rod 15 projectingfrom a repeater or follow-up motor device 16.

The repeater motor device 16 comprises a casing containing a flexiblediaphragm Ti clamped around its periphery in the casing in coaxialrelation with the rod 15 which is secured to the center of saiddiaphragm by followers 78 and "IS engaging opposite faces of thediaphragm, a shoulder 86 on said od engaged by the follower l8 and a nut8| on said rod engaging the follower '19-. The follower i9 is containedin a pressure chamber 82 open to pipe 62. The follower i8 is containedin a chamber 83 which is open to atmosphere through a passage 84. Twoprecompressed coil springs 85 and 86 contained in chamber 83 andencircling the rod 15 therein bear at one end against the follower 78for urging the diaphragm I"! and followers 78 and 2'9 in the directionof one or more stops H23 provided for contact by follower T9. Theopposite end of spring 85 is supported on a wall of chamber 83, whilethe opposite end of spring 85, which is disposed within spring 85, issupported on an adjustable spring seat 81: which. in turn is supportedon an adjustable stud 88 having screwthreaded engagement with thecasing. The spring seat 81 and stud 83 are centrally apertured throughwhich apertures the rod F5 extends to the exterior of the casing. A locknut 89 on stud 88 is provided for contact with the casing to secure thestud 88in an adjusted position.

The selector valve device may, for thepurpose of illustration, comprisea casing towhich are connected pipes 90 and 9|, and a fluid pressuresupply pipe 92 adapted to be supplied with fluid under pressure from anysuitable source. A plug valve 93 mounted in the casing is arranged to beturned by a handle 94 to either of two positions, one position beingthat in which it is shown and the other being indicated by a line 95.The plug valve 93 has two cavities 96 and 97, the cavity being providedfor connecting pipe 90 to the fluid pressure supply pipe 92 when handle94 is in the position shown in the drawing, and to. connect pipe 90 toan atmospheric vent passage 98 in the other position of said handle.Cavity 91 is provided for connecting pipe 9| to vent passage 98 withhandle 94 in the position shown in the drawing and to the fluid pressuresupply pipe 92 with said handle in its other position.

The two check valve and choke devices 5, 5a are of identical structure,each comprising a casing containing a check valve 99 for permitting flowof fluid under pressure in a direction from an inlet 60 to anoutlet |0|but to prevent reverse flow by way of said check valve. The casing also:has a communication by passing the check valve 99 and containing a chokeI02 for restricting flow of fluid under pressure in a direction from theoutlet to the inlet N10.

The check valve and choke device- 5' connects pipe 95 to pipe 32 leadingto the operator's control device 2 in such a manner as to permitrelatively rapid flow of fluid under pressure in the direction to saidpipe 32 past the respective check valve 99 but to restrict fiowin theopposite direction through choke I02, While the check valve and chokedevice So so connects pipe 9| to pipe 32 leading to the operator'scontrol device 2a as to permit relatively rapid flow of' fluid underpressure in the direction from pipe 9| to said operators controldeviceand restricted flow in the reversedireotion.

Operation-Fig. 1

Let it be assumed that the adjustable cam 39, the connectiontherebetween and diaphragm I! in the repeater motor 16 and the stud 88in said motor are all properly adjusted in each of the operators controldevices and that the adjustments in both of said control devices areidentical. Let it further be assumed that it is desired to control thedevice I from the operator's control device 2 and prevent control by theoperators control device 2a. To accomplish this, the handle 94 and valve93 of the selector valve device will be turned to the position shown inthe drawing for opening pipe 9! to atmosphere and for connecting pipe9%) to the fluid pressure supply pipe 92.

Now assume that fluid under pressure is supplied to pipe 92 and thenceto pipe 90 from which it will flow past check valve 39 in the checkvalve and choke device 5 and thence through pipe 32 to diaphragm chamber5! in the structure 49 and to the inlet valve chamber 29 in piston 22 ofthe supply and release valve mechanism 8 of the operators control device2.

The fluid under pressure thus supplied to chamher 5! in structure 49 ofthe operators control device 2 will deflect diaphragm 50 against spring555 and press the brake shoe 54 in frictional contact with the hub 44 ofthe operators lever 42 with suficient force to hold said lever in anyposition against accidental movement therefrom due for example tovibration.

With the operators control lever 42 of the valve device 2 in theposition shown in the drawing, the cam its will be adjusted to hold thepiston 22 in the position shown in the drawing, and with no fluidpressure in chamber l l above diaphragm ll), spring is will deflect saiddiaphragm to a. position defined by contact between the diaphragmfollower l4 and a shoulder l 04 in the casing part 9, in which positionthe release valve 28 will be seated and through the pin 34 the supplyvalve 33 will be unseated. When fluid under pressure is supplied to theinlet valve chamber 29 as above described, fluid will then flowtherefrom past the supply valve 33 to chamber 23 and thence to pipe 2:15and through choke to chamber H above diaphragm In. The pressure of fluidthus obtained in chamber H will, as it increases, deflect the diaphragmIll against spring [8 and permit the supply valve 33 to move toward itsseat, and this action will continue until said valve becomes seated in aposition determined by the position of piston 22. When the supply valve33 seats as just described it will prevent further flow of fluid underpressure to chambers 23, H and the connected pipe 24, thereby limitingthe pressure obtained therein to a chosen preselected degree, such asten pounds, corresponding to the position of piston 22 and adjustment ofcam 39 with the operators control lever in the position in which it isshown in the drawing.

Fluid under pressure thus supplied by the operators control device 2 tothe connected pipe 24 will flow through said pipe, past the double checkvalve 4 to the device I for controlling same, and will also flow fromsaid pipe through the pipe 62 leading to the operators control device 2aand to chambers 6! and 82 in the respective fulcrum device H35 andrepeater motor 18. This pressure acting on piston 51 in the fulcrumdevice I05 in the operators control device 2a will move said piston intocontact with the adjacent end of stop member 59, which position it willalways occupy when subject to pressure of fluid at or exceeding thepressure provided in the delivery pipe 24 connected to the operatorscontrol device 2. The pressure of fluid obtained in chamber 82 of therepeater motor 16 of the operator's control device 2a from the operatorscontrol device 2 with its lever 42 in the position shown in the drawingwill just balance the opposing pressure of the respective springs 85, 86on'diaphragm 91, so that said springs will be able to hold the follower19 just in contact with the stop I03. With the piston 5i of fulcrumdevice Hi5 and diaphragm ill of the repeater motor H5 in the operatorscontrol device is positioned, as just described, by fluid under pressuresupplied from the operators control device 2 with its control lever 42in the position shown in the drawing, the lever 42 in the operatorscontrol device 2a will be caused to assume the same position.

When the selector valve device 3 is adjusted to render the operatorscontrol device 2 efiective and the operators control device 2aineffective to control the device I, the pipe 8! is opened to atmosphereas above mentioned, and as a result, diaphragm chamber 54 and the supplyvalve chamber 29 in the operators control device 2a, will likewise beopened to atmosphere. In the operator's control device 2a, the diaphragm'50 in structure 39 will therefore be deflected in a direction torelieve pressure of the shoe 54 against hub 49 of the operators lever topermit free movement of said lever, while opening the supply valvechamber 29 to atmosphere will, with the piston 22 and lever 42 in theposition shown in the drawing, permit the supply valve 33 to be open forconnecting diaphragm chamber l4 and the connected pipe .2 1 to therespective pipe 32 and thus to atmosphere. With the pipe 24 connected tothe operators control device 2a thus open to atmosphere, chamber 6! inthe fulcrum device IE5 and diaphragm chamber 82 in the repeater motorit, in the operators control device 2 will also be open to atmospherethrough the respective pipe 62 and said pipe 24.

Summarizing, it will be noted that when the operators control device 2is selected for controlling the device i, the friction shoe 55 thereinis rendered effective, the supply and release valve mechanism 8 thereinis supplied with fluid under pressure from the supply pipe 92 andcontrols supply of fluid under pressure to the device l, while chambers8! and 82 in the fulcrum device ['65 and repeater motor '16 therein areopen to atmosphere, and with the respective operators control lever 42in the position shown in the drawing, the respective fulcrum piston 51will just contact the inner end of stud 59, while diaphragm follower E9of said repeater motor will just contact the stop I03. On the otherhand, in the operators control device 2a, the brake shoe 54 isineffective, no fluid under pressure is supplied to the supply andrelease valve mechanism 8, the fulcrum piston 57 will be urged intocontact with the adjacent end of stop member 53 by pressure of fluidsupplied by the supply and release valve mechanism 8 in the operator'scontrol device 2,

and diaphragm H in the repeater motor '16 will be subject in chamber 32to pressure of fluid supplied by said mechanism, which pressure willjust balance that of springs and 86 with the diaphragm follower is incontact with stop I93, said diaphragm and follower and the fulcrumpiston 5'! therefore occupying the same positions as the correspondingparts in the operator's control device 2, and when so positioned, theconnections between lever 64 and the adjustable cam 39 and rod 15 in therepeater motor 16 in the opera.- tors control device 2a will be adjustedto cause the respective lever 42 to occupy the same position as theoperators lever 42 in the operators control device 2.

Now let it be assumed that lever 42 of the operators control device 2 isturned clockwise out of the position in which it is shown, to any chosendegree. This movement will be resisted bypressure of friction shoe 54which however upon cessa tion of such movement will securely hold thelever 42 in the chosen position. As the lever 42in the operators controldevice 2 is thus turned in a clockwise direction, the lever 64 due toits connection with cam 39 will be turned in a counterclockwisedirection about its connection at pin with the repeater motor 16, theparts of which will remain in the position shown in the drawing due tothe action of springs 85 and 86. As a result, the fulcrum piston 58 willbe moved by the lever 64 out of contact with stop 59, and since chamber6| is open to atmosphere, this movement of piston will be unopposed. Itwill thus be seen that in the operators control device 2 the lever 64and piston 5'! simply idle upon movement of lever 42, and it is to benoted that the space below piston 51 is sufficient to permit movementthrough the full range of movement of lever 42 from the position inwhich it is shown to the opposite end of the slot 48.

When lever 42 in the operators control device 2 is operated as justdescribed, the cam 39 will move the piston 22 in the direction ofdiaphragm if! an amount proportional to the extent of movement of saidlever, and this movement of said piston will initially be relative tothe diaphragm l0, and hence the supply valve 33 which will initially beheld stationary by the control spring [8 acting in said diaphragm. As aresult, the piston 22 will be moved out of contact with the supply valve33 whereupon fluid under pressure will flow past said valve to chamber21 and thence to the connected pipe 24 and from said pipe past thedouble check valve 4 to the device I for adjusting said device.

As fluid under pressure is thus flowing to the device I from theoperators control device 2, it will also become effective through choke25 in chamber ll above diaphragm I!) and deflect said diaphragm againstspring I8 and this deflection and consequent movement of the supplyvalve 33 therewith will continue until said valve seats to preventfurther flow of fluid under pressure to the device I for limiting thepressure therein to a degree corresponding to the position of piston 22and in turn the position of lever 42.

Fluid under pressure thus supplied by the operators control device 2 tothe connected pipe 24 for controlling operation of the device I alsoflows through the pipe 62 connecting said pipe 24 to the operatorscontrol device 2a to piston chamber 6! in the fulcrum device H35 thereinfor holding the respective fulcrum piston 51 against stop 59, and alsoto diaphragm chamber 82 of the respective repeater motor 75. Thepressure of fluid thus obtained in chamber 82 in the operators controldevice 2a will deflect the diaphragm ll against springs 85 and 86 to aposition in which the pressure of said springs will be increasedsufliciently to counterbalance the pressure of fluid, and this movementwill actuate lever 64 to turn lever 42 of theoperators control device 2ato a position corresponding to that of the actuating diaphragm 11. Theconnections betweenlever 64, the adjustable cam 39 and rod 15 of therepeater motor 16 will be so adjusted, and the pressure of spring 86will be so regulated by the adjusting stud 88, that for the positionassumed by the diaphragm 11 in response to pressure of fluid provided inchamber 82 by operation of the operators control device 2, the lever 42of the operators control device 2a will be moved to the same position asoccupied by lever 42 of the operators control device 2.

Now assume that the lever 42 of the operators control device 2 is movedfurther in a clockwise direction for increasing the pressure of fluid inthe device l to be controlled. This increased pressure will becomeefiective in the repeater motor 16 of the operators control device 241to cause the respective lever 42 to assume the same position as that ofthe operators control device 2.

Assume that, the lever 42 of the operators control device 2 is occupyinga position to the right of that shown in the drawing for supplying fluidat a chosen pressure to the device 2, and that it is desired to reducethis pressure. To accomplish this, the lever 42 of the operators controldevice 2 will be moved in, a counterclockwise direction to a positioncorresponding to the pressure desired in device I.

In the operators control device 2, this movement of lever 42 andconsequently of cam 39 will permit the piston 22 to be moved upwardly byspring 36 and pressure of fluid in chamber 23, and with the supply valve33 seated as previously described, said valve will move with said pistonand pull the release valve 28 off of its seat, since at this time saidseat will be held stationary with diaphragm It by pressure of fluidacting in chamber H on said diaphragm. Upon opening the release valve28, fluid under pressure will then. flow from chamber 23 and theconnected pipe 24 and device I to atmosphere, and the pressure of fluidin diaphragm chamber ll will reduce with that in chamber 23. As thepressure in chamber ll thus reduces, spring f8 will deflect diaphragmIll and consequently the seat for the release valve 28 upwardly, andthis movement will continue until the pressure of fluid controllingthedevice becomes reduced suflioiently to permit the seat for therelease valve to be moved into engagement therewith, for therebylimiting the reduction in pressure in chambers 23 and H and in thedevice I to a degree corresponding to the position ofsaid release valve,and hence corresponding to the position of piston 22 lever 42 of theoperators control device 2.

As the operators control device 2 thus operates to reduce the pressureof fluid supplied thereby to a degree corresponding to the change inposition of; the respective lever 42, a corresponding reduction inpressure of fluid occurs in chamber 82 in the repeater motor 15 of theoperators control device 2a which permits springs 85 and 86 in saidmotor to actuate diaphragm llto move the respective operators lever to anew position, corresponding to said reduction in pressure of fluid and;hence corresponding to the new posh tionvof lever 42 in, the operatorscontrol device 2.

It will now be seen that regardless of the position towhich the lever 42in the operators control device 2. is moved, the repeater motor l5 inthe operators control device 2a will move lever 42 of the operatorscontrol device 2a substantially in unison and to a correspondingposition.

If it is desired that the control station he changed from the operatorscontrol device 2 to the operators control device 2a, the selector valvedevice 3 15 operatedto its otherpositlon for opening pipe 90 toatmosphere and for supplying fluid under pressure to pipe 9|.

The opening of pipe 9!! to atmosphere will release fluid under pressurefrom diaphragm chamher in the structure 49 in the operators controldevice 2 for rendering the respective brake shoe ineffective, and willalso result in release oi fluid under pressure from the respectivesupply valve chamber 29. Pressure of fluid in chamber 23 in theoperators control device 2 will then blow the supply valve 33 from itsseat against the small resistance of spring 35, and be dissipated alongwith that in the connected pipes 2d and 62 and in the fulcrum pistonchamber ill and repeater diaphragm chamber 82 in the operators controldevice 2a. In the operators control device 2a the parts of the repeaterportion 56 will therefore assume the position shown in the drawing andthe fulcrum piston 51 will be freed to move with the control lever 42.

When fluid under pressure is supplied to pipe ti by turning the selectorvalve 3 as above mentioned, the supply and release valve mechanism 8 inthe operators control device is will operate to supply fluid underpressure to the connected pipe 24 and thence by way of the pipe 62 con--nected to the operators control device 2 to the fulcrum piston chamber5i and repeater diaphragm chamber 82 therein. The pressure obtained inchamber ill in the operators control device 2 will move the respectivepiston 53 to the position shown in the drawing to provide a fu1- crumfor the connected lever 64 for rendering the respective repeater portionis eflective to ad" just the position of the respective operatorscontrol lever 4.2 in accordance with pressure of fluid provided inchamber 82 of said repeater portion.

From the above description it will be evident that with the apparatusconditioned as just described, providing for control of device 8 by theoperators control device 2a, the lever d2 of the operators controldevice 2 will follow movement of lever 42 of the operators controldevice 2a and always assume a corresponding position.

When the selector valve device 3 is operated to L transfer the controlstation to the operators control device 2a, it will be noted that chokeM2 in the check valve and choke device 5 restricts release of fluidunder pressure from diaphragm chamber iii in the structure iii of theoperators control device 2, and at the same time the pressure of fluidsupplied to pipe ill is ermitted to flow at a relatively rapid rate tothe corresponding chamber in structure 48 of the operators controldevice is. The purpose of this is to ensure that the brake shoe 5% inthe operators control device 2a at the new control station, will becomeeffective before the corresponding brake shoe, at the station from whichcontrol is being removed, becomes ineffective, in order to ensureagainst any accidental change in position of the operators controllevers 12 during this change in con trol stations. The choke Iild in thecheck valve device 5a functions in a like manner in changing controlstations from the operators control device 2a to the operators controldevice 2.

Before the operators control devices 2 and 2a are operated, as abovedescribed, certain adjustments are required to ensure that the pressureof fluid supplied by both of said devices to the respective pipes 2 5will be the same for the same positions of the operating levers 52. Toeffect these adjustments, the lever 42 of each device will be moved tothe right hand end of the respective slot 48, and assuming that thesupply valve chamber 29 is supplied with fluid under pressure, the screwZll is then adjusted to regulate the pressure of spring it against thediaphragm ill until the pressure obtained in chamber 23 and theconnected pipe 2 2 (as registered on a gage) is of the desired degree,such as pounds. After this adjustment is completed, the lever 42 ismoved to the left hand end of slot Aid, and the screw 45 with theeccentric portion l l is turned to adjust this end of the cam 39 and theposition of piston 22 until the pressure in chamber 23 and the connectedpipe 2A is at the desired minimum degree, such as the 10 pounds abovedescribed. With the two operators control devices 2 and 2s thus adjustedto provide the same pressures in the respective pipes 24 in the twoextreme positions of the respective levers 42, and with identical cams39, the pressure of fluid provided in pipes 24 of the two controldevices 2, as will be the same for all identical positions of the twooperators control levers 42.

DescriptionFig. 3

The invention asembodied in the structure shown in Fig. 1 is limited totwo control stations or two operators control valve devices 2, 2a, butif desired, may be extended to any desired number of control stations inthe manner shown in Fig. 3 wherein it is shown applied to three controlstations.

As shown in Fig. 3, 2, 2a designates operators control devices, likethose shown in Fig. 1, adapted to be located at two control stations,while 221 designates a like operators control device for the thirdstations. 5 and 5a and d designate check valve devices and chokes likethose required for the two station control, while 5b and 4a indicatelike devices required in connection with the additional control stationwhere the operators control device 21) is located. Reference numeral usedesignates a selector valve device having three positions, correspondingto the number of con trol stations and operative in each differentposition to supply fluid under pressure from the fluid pressure supplypipe 92 to the pipe 98, 9! or Sic. leading to the operators controldevice 2, 2a or 2b which is selected to control the device 5, while atthe same time opening to atmosphere the other two of said pipes.

According to this modification, an intercepting valve device H3? isprovided at each control station. The intercepting valve devicecomprises casing having a chamber ms containing a valve its arranged tocontrol communication between said chamber and chambers H9 and iii.Chamher i H is open to atmosphere through a passage H2 and is formed atone side of a piston M3 at the opposite side of which is a controlchamber lit. When fluid under pressure is supplied to chamber l I l, thepiston will operate valve N38 to close communication between chambersIE8 and lit and to open chamber N38 to atmosphere through chamber HI andpassage H2. When chamber lid is void of fluid under pressure a spring H5in chamber ill) will move valve N39 to the position shown fordisconnecting chamber i953 from chamber ill and for connecting chamber558 to chamber H0.

At each control station chamber ")8 is connected to pipe 62 from therespective operators control device 2, 2a or 2b, while chamber lid isconnected to the fluid pressure supply pipe 99, ill or Ma leading tosaid operators control device. Chambers ill! in all of the interceptingvalve devices I07 are connected together by a pipe I I6 and 11 to thepipe connected to the device I' to be controlled.

In operation, assume that the selector valve device I 06 is in theposition shown in the drawing supplying fluid under pressure to pipe 99and opening pipes 9| and 9Ia to atmosphere. Fluid under pressure willthen flow through pipe iii! to the operators control device 2, selectedfor controlling operation of the device I, and in said operators controldevice the brake shoe 54 will be rendered effective and the supply andrelease valve mechanism 8 will be rendered effective upon movement ofthe lever 42 to supply fluid to the respective pipe 24 at a pressurecorresponding to the position of said lever. Fluid under pressure thussupplied by the operators control device 2 to the respective pipe 24will then flow through the double check valved, a pipe I II, and throughthe double check valve device to to the device I for actuating same.

Fluid at the pressure thus supplied to the device I will becomeeffective through pipe H6 in chamber III] of all of the interceptingvalve devices IIl'I. In the intercepting valve device Ill'l connected tothe operators control device 2, pressure of supply in pipe 90 iseffective in chamber I Hi to actuate piston H3 for actuating the valve Ito to the position for closing communication between chambers I08 and Hand for opening the former chamber to atmosphere. Hence, chamber 6| inthe fulcrum device I05 and chamber 82 in the repeater motor I6 in theoperators control device 2 at the control station will be open toatmosphere, the same as in the structure shown in Fig. 1.

Pipes SI and 9 la being both open to atmosphere in the position of theselector valve device IDS providing for control of the apparatus by theoperators control device 2, the brake shoe 54 in the operators controldevices 2a and 2b will be rendered ineffective, and the piston chambersII i in the intercepting valve devices I'IJI, associated with theoperators control device 2a and 2b at the non-control stations, willalso be open to atmosphere permitting each of the respective valves N19to close communication between chambers I08 and III and to open chamberits to chamber I I'll. As a result, fluid under pressure supplied by theoperators control device 2 at the control station for operating thedevice I and supplied to chamber I I0 in the intercepting valve devicesIII! at the two non-control stations, will flow from said chamberthrough the respective pipe 62 to actuate the fulcrum piston 51 in eachof said devices to the position shown in Fig. 1, and to become effectivein diaphragm chamber 82 of the respective repeater motor I6, wherebyupon operation of the lever-42 of the operators control device 2 at theselected control station the levers 42 of the operators control devices2a, 21) at the non-control stations will follow and always occupy thesame position as that occupied by said lever at the control station.

Now assume that it is desired to transfer the control of device I fromthe operators control device 2 to the operators control device 2a. Toaccomplish this the selector valve device I05 will be moved to theposition for connecting pipe SI to the fluid pressure supply 92 and foropening pipes 90 and 9Ia to atmosphere. The brake shoe 54 in theoperators controldevice 211 will therefore be rendered eflective; andthe intercepting valve device I01 associated with the operators controldevice 2a will operate to open to atmosphere the respective pipe 62 andthereby the connected fulcrum piston chamber 6i and repeater motordiaphragm chamber 82. The operators control device 2a is now efiectiveto control the device I. The intercepting valve devices I01 associatedwith the operators control devices 2, 2b, at the non-control stations,will however remain in the position shown in the drawing to permit fluidunder pressure supplied by the operator's control device 2a forcontrolling the device I to become efifective in the fulcrum pistonchambers 55 and. repeater motor diaphragm chambers 82 of the operatorscontrol devices 2a, 21) so that the control levers 42 thereof will movewith and assume positions corresponding to the control lever 52 of theoperators control device 2a.

In a similar manner, if it is desired to employ the operators controldevice 2b for controlling the device I, the selector valve device I06will be operated to open pipe 9Ia to the supply pipe 92 and to open toatmosphere the pipes and 9|, whereby the intercepting valve devicesIIl'I will be adjusted to cause the levers 42 of the operators controldevices 2, 2a to move with and always occupy the same position as thelever 42 of the operators control device 2b at the control station.

Summary It will now be seen that I have provided in a multiple controlstation apparatus embodying an operators control device at each stationand means for selectively rendering any one of said devices eiiectiveand all others ineffective for controlling a desired operation, andstructure which is operative, regardless of the selected control device,to cause the control levers of the inefiective control devices to movewith and always assume the same position as occupied by the controllever of the selected device.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In combination, two operators control means each comprising a leverhaving a zone of movement, self-lapping controlling structure operativeby movement of said lever in said zone, and repeater means controlled bysaid structure in the other control means for automatically positioningthe respective lever in accordance with the position of the other lever,and other means for selectively rendering the structure of eithercontrol means efiective to control the repeater means in the othercontrol means and for at the same time rendering the other structureinefiective.

2. In combination, two operators control means each comprising a leverhaving a zone of movement, holding means adapted to cooperate with saidlever for holding it in any desired position, self-lapping controllingstructure operative by movement of said lever in said zone, and repeatermeans controlled by said structure in the other control means forautomatically positioning the respective lever in accordance with theposition of the other lever, and other means for selectively renderingthe structure of either control means efiective to control the repeatermeans in the other control means and for at the same time renderin theother structure ineffective, each control means further comprising meansresponsive to operation of said other means for rendering said holdingmeans eiIective and ineffective upon rendering the respective controlmeans effective and inefiective, respectively.

3. In combination, two operators control means each comprising amanually operable lever having a zone of movement, self-lapping valvemeans operable by said lever in said zone to supply fluid at a pressurecorresponding to the position of said lever in said zone, and repeatermeans adapted to be operated by fluid at a pressure corresponding to anyposition of said lever in said zone to move said lever to said position,and means for selectively rendering either valve means eiiective tosupply fluid under pressure to the repeater means in the other controlmeans and for at the same time rendering the other valve meansinefiective to supply fluid under pressure to the other repeater means.

4-. In combination, two fluid pressure supply pipes, two fluid pressurecontrol pipes, two operators control means each comprising a manuallyoperable lever having a zone of movement, and valve means operable bysaid lever to supply fluid from one of said supply pipes to one of saidcontrol pipes at a pressure corresponding to the position of said leverin said zone, selector means for selectively supplying fluid underpressure to either one of said supply pipes and for at the same timeopening the other supply pipe to atmosphere, each control means beingalso operable to release fluid under pressure from the respectivecontrol pipe to the respective supply pipe upon opening the last namedpipeto atmosphere, and each control means further comprising repeatermeans arranged to be responsive to pressure of fluid in the control pipeconnected to the other control means and operative upon supply of fluidunder pressure to the last named pipe to position the respective leverin the zone in accordance with the pressure of such fluid.

5. In combination, a device to be controlled, two operators controlmeans each comprising a lever having a zone of movement, and valve meansoperable by said lever to supply fluid at a pressure corresponding tothe position of said lever in said zone, means for conveying fluid underpressure from said control means to said device comprising a doublecheck valve operable by fluid under pressure supplied by either controlmeans to open communication therebetween and said device and for closingcommunication between said device and the other control means, each control means further comprising repeater means adapted to be operated byfluid under pressure for moving the respective lever to a positioncorresponding to th pressure of such fluid, selector means forselectively rendering either of said valve means effective to supplyfluid under pres sure and the other inefiective, and means controlling afluid pressure supply communication between said device and eachrepeater means operable upon operation of said selector means to rendereither of said control means efiective to close the fluid pressuresupply communication to the respective repeater means and to open thefluid pressure supply communication to the other repeater means.

6. In combination, two fluid pressure supply pipes, two fluid pressurecontrol pipes, two operators control means each comprising a manuallyoperable lever having a zone of movement, and valve means operable bysaid lever to supply fluid from one of said supply pipes to one of saidcontrol pipes at a pressure corresponding to the position of said leverin said zone, selector means for selectively supplying fluid underpressure to either one of said supply pipes and for at the same timeopening the other supply pipe to atmosphere, each control means beingalso operable to release fluid under pressure from the respectivecontrol pipe to the respective supply pipe upon opening the last namedpipe to atmosphere, each control means further comprising repeater meansarranged to be responsive to pressure of fluid in the control pipeconnected to the other control means and operative upon supply of fluidunder pressure to the last named pipe to position the respective leverin its zone in accordance with the pressure of such fluid, a fluidpressure adjustable device, and means connecting said control pipes tosaid adjustable device for conveying fluid under pressure thereto foradjustin same, the last named means including a double check valveoperable upon supply of fluid under pressure to either one of saidcontrol pipes to open communication therebetween and said adjustabldevice and to close communication between said adjustable device and theother control pipe.

7. In combination, two fluid pressure supply pipes, two fluid pressurecontrol pipes, two operators control means each comprising a manuallyoperable lever having a zone of movement, and valve means operable bysaid lever to supply fluid from one of said supply pipes to one of saidcontrol pipes at a pressure corresponding to the position of said leverin said zone, selector means for selectively supplying fluid underpressure to either one of said supply pipes and for at the same timeopening the other supply pipe to atmosphere, each control means furthercomprising repeater means adapted to be operated by fluid under pressurefor positioning the respective lever in accordance with the pressure ofsuch fluid, and means associated with each control means operable uponopening to atmosphere the respective fluid pressure supply pipe to opencommunication between the respective repeater means and the control pipeconnected to the other control means and operable upon supply of fluidunder pressure to the respective fluid pressure supply pipe to closecommunication between the respec tive repeater means and last namedcontrol pipe and open the respective repeater means to atmosphere.

8. In combination, two fluid pressure supply pipes, selector meansoperative to supply fluid under pressure to either one of said supplypipes and to at the same time open the other supply pipe to atmospheretwo fluid pressure control pipes, two control devices each comprising amanually operable lever having a zone of movement, and self-lappingvalve means operable by said lever to control a communication forsupplying fluid from one or" said supply pipes to one of said controlpipes at a pressure corresponding to the position of said lever in saidzone, each control means being also operable upon opening the respectivesupply pipe to atmosphere to release fluid under pressure from therespective control pipe via said communication.

9. In combination, two fluid pressure supply pipes, two fluid pressurecontrol pipes, two control devices each comprising a manually operablelever having a zone of movement, and self-lapping valve means operableby said lever to control a communication for supplying fluid from one ofsaid supply pipes to one of said control pipes at a pressurecorresponding to the position v of said lever in said zone, selectormeans opera- 15 ply pipe operable upon supply of fluid under pressurethereto to render said holding means effective and operable upon releaseof fluid under pressure therefrom to render said holding meansineffective.

10. In combination, two fluid pressure supply pipes, two fluid pressurecontrol pipes, two control devices each comprising a manually operablelever having a zone of movement and self-lapping valve means operable bysaid lever to control a communication for supplying fluid from one ofsaid supply pipes to one of said control pipes at a pressurecorresponding to the position of said lever in said zone, selector meansoperative to supply fluid under pressure to either one of said supplypipes and at he same time release fluid under pressure from the otherpipe, each control means further comprising holding means for holdingthe respective lever in any selected position, and means open to therespective supply 1 pipe operable upon'suppiy of fluid under pressurethereto to render said holding means effective and operable upon releaseof fluid under pressure therefrom to render said holding meansineifective, and means for restricting release of fluid under pressurefrom each of said supply pipes and for providing relatively rapid supplyof fluid under pressure thereto, upon operation of said selector means.

11. In combination, a fluid pressure adjustable device, a plurality ofcontrol means for controlling said device, each comprising a manuallyoperable lever having a zone of movement, self-lapping valve meansoperable by said lever for supplying fluid under pressure to said deviceat a pressure corresponding to the position of said lever, and repeatermeans operable by fluid under pressure to move said lever to a positioncorresponding to the pressure of such fluid, selector means adjustableto selectively render any one of control means efiective to supply fluidunder pressure to said device and to at the same time render all othercontrol means ineffective to control said device, and means operableupon operation of said selector means to render any one of said con- Itrol means effective to control said device to also effect a release offluid under pressure from the respective repeater means and to supplyfluid under pressure from said device to all other repeater means.

12. In combination, two operator's control means each comprising arockable lever having a zone of movement, self-lapping valve meansoperable by said lever to supply fluid at a pressure corresponding tothe position of said lever,

to render the repeater motor of the other control means ineifective tomove the respective lever.

13. In combination, two operators control means each comprising a,rockable lever having a zone of movement, self-lapping valve meansoperable by said lever to supply fluid at a pressure corresponding tothe position of said lever, a fluid pressure controlled repeater motoradjustable to a position corresponding to the pressure of such fluid,lever means connecting said motor to said lever for adjusting said leverby said motor, a fulcrum for said lever means shiftable to one positionupon supply of fluid under pressure to said motor to render said motoreffective to adjust said lever and operable upon release of fluid underpressure from said motor to render said lever means movable by saidlever relative to said motor, means for conveying fluid under pressurefrom the valve means in each control means to the repeater motor in theother control means, and means for selectively rendering the said valvemeans in either control means ineffective to supply fluid under pressureand at the same time to release fluid under pressure from the repeatermotor and fulcrum means in the other control means.

14. In combination, two operators control means each comprising arockable lever having a zone of movement, shelf-lapping valve meansoperable by said lever to supply fluid at a pressure corresponding tothe position of said lever, a fluid pressure controlled repeater motoradjustable to a position corresponding to the pressure of such fluid,lever means connecting said motor to said lever for adjusting said leverby said motor, a fulcrum for said lever means shiftable to one positionupon supply of fluid under pressure to said motor to render said motoreffective to adjust said lever and operable upon release of fluid underpressure from said motor to render said lever means movable by saidlever relative to said motor, means for conveying fluid under pressurefrom the valve means in each control means to the repeater motor in theother control means, each control means further comprising holding meansoperable by fluid under pressure to hold the respective lever againstaccidental movement and rendered ineffective upon release of such fluidunder pressure, and means for selectively rendering said valve means ineither control means ineflective to supply fluid under pressure and forat the same time releasing fluid under pressure from the respectiveholding means, and from the repeater motor and fulcrum means in theother control means.

ROY R. STEVENS.

REFERENCES CITED UNITED STATES PATENTS Name Date Campbell May 26, 1931Number

